Pulp-thickening machine



C. H. ALLEN.

PULP THICKENING MACHINE.

APPLICATION FILED MAY 28, 1920.

13% 1 ,364. Patented July 4, 1922.

VENT 17E. mxz M,

i MAINE.

CARLTON H. ALLEN, OF MILLINOCKET,

NORTHERN PAPER COMPANY, OF

Application filed May 28,

To all whom it may concern:

Be it known that I, 'CARUroN H. ALLEN, a citizen of the United States,residingat Millinocket, in the county State of Maine, have inventedcertain Improvements in a-Pulp=Thickening Machine, of which thefollowing description, in cona specification, like reference characterson the drawings indicating like parts in the several figures.

This invention relates to a thickener or washer for .pulp. According tothe usual processes of making pulp an excessive quantity of water isused for the purpose of facilitating the screening operation andconsequently it is necessary later to thicken the pulp before it goes tothe paper machine. For instance, a normalconsistency for the pulpimmediately after the screening operation is approximately three-tenthsof one per cent, while it is desirable that this consistency beincreased to from two to five per cent before the pulp is delivered tothe paper machine. This may moving part of the water in which the solidmaterial is suspended and pulp thickeners operating on this principleare known at the present time.

It is the chief object of the present invention to devise :an apparatusof this character which will I have a greater capacity for a given areaof screening or filtering surface than similar apparatus heretoforeused, which will produce more uniform results, which can be economicallymanufactured, in which repairs ,can readily be made, and which generallyshall be an improvement on apparatus of this character heretoforeproposed.

The nature of the invention will be readily understood from thefollowing description whenread in connection with the accompanyingdrawings and the novel features will be particularly pointed out in theappended claims.

Referring now to the drawings,

Figure 1 is a front elevation of a pulp thickening machine embodyingthe-invention. in the form. at present preferred Fig. 2 is a transversecross sectional View of the machine shown in Fig. 1 showing it inconnection with certain apparatus for su plying pulp thereto; and

1g. 3 is a vertical cross sectional View at Specification of LettersPatent.

of Penobscot and sectional outline, the nection with the accompanyingdrawings, is

be done by re-- I they MAINE, ASSIG-NOR 0F ONE-HALF TO GREATMILLINOCKET, IEAINE, A CORPORATION OF PULP-THICKENING- MACHINE.

Patented July 4%, 1922. 1920. Serial n. 384,942.

one end of the machine, the section being taken substantially on theline 3-3, Fig. 2. The apparatus shown comprises a rotary drum or filterdesignated in general at 2.

This drum is mounted to revolve about a horizontal axis and is polygonalin cross particular form shown having sixteenv faces. The drum may bebuilt in any suitable manner but preferably it comprises a series ofplates or ribs 3, approximately annular in shape, spaced apart by, andinterlocked or cast with, a series of longitudinally extending bars 4.The plates 3 are grooved to support a series of small tubes or rods 5which extend the entire length of the drum and support a screen or wirecloth 6 that forms the filtering surface. At each end the drum isprovided with an annular member" 7, Fig. 3, secured rigidly thereto andforming a part thereof, and each of these members is bolted or rivetedto the projecting flange of a spur gear 8.

The filtering drum is supported in a casing comprising a lower or baseportion 10 and an upper portion 12 which is hinged to the lower portionat 14. Normally these two parts occupy the, positions in which are shownin F ig. 2, a tight joint be ing provided between them by a suitablegasket. This casing is provided with bearlng members 15 at its oppositeends which support sleeve-like extensions 16, Fig. 3, projecting fromthe hubs of the respective spur gears 8. The upper portion 12 of thecasing is provided with bearings which support a shaft 17 having twopinions 18-18 thereon which mesh with the respective spur gears 8 at theopposite ends of the drum and drive the drum, the shaft itself beingdriven by a .belt connection to a pulley 19 fast thereon.

The pulp to be thickened is conducted to a head-box 2 which is connectedby a pipe 21 to the lower part 10 of the casing, the flow of pulp to thecasing being controlled by a valve 22. The head-box is higher than thecasing and the valve 22 is so ad'usted that the casing is substantiallyfille with pulp at all times during the normal operation of theapparatus, so that the drum 2is completely submerged. As shown in Fig.2. the casing is provided with a delivery or discharge oening 24 at oneside of thedrum, and t e portion of the casing immediately below thisopening consists of a;

plate 25fleiitendingthe e ilengt of, he

cylinder and having an iniifi Surface curyed concentrically: with the@This? plate is adj ust'ably secured. at its ends thes'tationary partsofthe casinglby bolts 26-26 Pa i g h e h k s t na d Po i n v of {theplate, y 1 The clearance between the roairing en s ems r a s-lit e, p ti adjusted thattheflow of the l htkened p pgt fough l i eherg e n:

ing s prevented A similar. construction is 1 provided, aboye thedischarge; "opening and comprises a plate secured b" b useass in theconstruction just descrih ed. i {It should be noted thatltheinne!Surfaces 0 e c ed Pla es a t dr2 J QfQ uch dimensions vci'rcgulinfe'rentially .of"th e drum that they cover, {at all times, atleast two, of the projecting edges 29 that separate the adjacent fiatfaces of the drum. In other words, they each lcoyer more than one flatfalcejofthe drum;

: When he apparatusj isfin casing is filled with pulpor fstuifhjtheen irdr m ngfwbm e ii nd he m is driven very slowly in .the directionindicated by the arrow, Fig. 2. A large proportion of .thewaterdrains'through the screen and runs out the opposite ends of'the drum, which areopen, into the discharge 30 30. This leaves aflaye-r ofthickslushypulpon thesurface ofthe dr l ing-which seals. the

space between? the plate ilfifand the ect; ing edges29 ofthedrum. 7 Asthe drum ro.- tat'es slowly past ,the discharge opening; 24 the;thickened pulp. held} in the sector-like space ,lformed between one ofthe fiat .faces of the d r im vand the inner-face oftheplate 25 isdischarged through the ope-nin 2,4,but an rush of the thin stock or untiokened. pu p throughwthis'opening is prevented by the presence of thelayer pulp in the thin clearance pace betweennthe edges 29 ofthe drumvand the inner curved surface oflthe drum than is the lower plate 25 h Inthis connectionit may ,be pointed out that the machine can be operatedtothicken pulp when the drum is rotated ineither direc-j tion and that itis not necessary to have the drum entirely submerged, although theapparatus operates more rapidly, or has a greater capacity, other thingsbeing equal, when it is submerged,

the opening .24 1 substantially; continuously 1 and is of :a compara ivly lun f mic s str ency; L; Furthermore,=.-this consistency can he aredl y -Yeryi atm h e -s Pulp i lt box; QO onhy changingthespeed ofrotation.

Us rially -the speed of rotation: is very slow ay:'fo l exampleggttbm e7 e i ns. Per mini be i i tli eaxlugii hei are ru l ta ion liygp pe 22%led threng lt eih l ew sh u tionedl; 'withi'n the drum. opposite the Idisharge pen ngfi -g i t er e ldf ma oles are;drumiatheliorwe d side ofthis pipe so that} theyld ,2 eet. a spray of clean -:water against.theinl et r f. ln zorden. to p 'event; the unthickened. pulp from imaginat the ends; of the drums a novel packlng preferably is; used; ,As shownFig- 3; t e nd o thel a' q i 'i Pr ed witha circular lip #33surroundinglthedrum to: i receive packing 34,1 and a plate :35. is.secured touthe outer edge of; the lip 33: by screws ,or halts to holdthe packing in place. Th s? Pa ng -p f i' ysts f end:

leglrubber ,tube'finflated s uat i exerts a yielding pressure againstthe outer surface of-the drummember'Z and: maintains atightjointhetyveenlthe endsof the drum and the casing."v Y 1 .lflwlapparatus; substantially. the entire screening or filt ering 7 surfaceof the drum ,is utilized at an; times during. {the normal" operation of"that, shite;

'themachine. Due tojthisr-i'fact and to the a further fact that {theapparatus is operated undena certain hydraulic headyfitperforms thepulpthickeninguoperation much more rapidly than dotheprior machines designedfor this Work. a Furthermore, the machine produces more uniform results;Q That :is,

thetthickened pulp'fdischar qg'etil from fthe inachine is of a'moremniform consistency than isthat produced by the prior. machines withwhichmI am familiar. ,u Theifp-articular machine shown is designednafor.washing or thickening sulphite stock butpa machinepf thelsame characteris adapted :for use with ground wood pulp; although l, prefer to use adrum hav-inga greaterj.11umber-of,flat faces foroperating on ground woodulp. It will be understood thatwhile I have herein referred toz the drumas of polygonal shape cross section, since this construction isconvenient to] manufactureland operates satisfactorilyythat a truepolygonal shape not absolutely essential to producing the resultsabovedescribed, butthat the faces, of theidrum. may be somewhat convex orconcave if desired. y Y 1 v It will also be understood that while I haveherein shown and describedv the best er'n bodimentof the invention oi hch 1 am at which said drum may be ill present aware, this embodiment maybe modified in many particulars without departing from the spirit orscope of this invention.

What is claimed as new is 1. A pul thickening apparatus compris ing, incom ination, a lterlng drum, means for driving said drum, andyareservoir 1-n submerged in pulp, opening at one side discharge ofthickened said reservoir having an of said drum for the pulp.

2; A pulpthickening apparatus vcomprls ing, in combination, a filteringdrum, means for driving said drum, a reservoir in which said drum-maysubmerged in pulp, said reservoir having an opening at one side of saiddrum through which the thickened pulp is discharged, and means forpreventing the flow of unthic'ke'ned plup from'said reservoir-throu hsaid opening.

3. A pu p) thickening apparatus, comprising, in com ination, a filteringdrum, means for driving said drum, 'a'casi'ng in which said dru'mismounted, said casing torming a reservoir for unthickened pulp and havingan opening therein at one side of said drum for the discharge ofthickened pulp, said openingbeing below the normal level of the pulp insaid casing, and means for prevent mg the flow of unthickenedpulp'through said discharge opening.

4. A pulp thickening apparatus comprising, in combination, for-drivingsaid drum, a casing in which saididrum is mounted, said casing having aat one side of said drum,

discharge opening and stationary parts at opposite sides of said openingfitting close to the peripheral surface of the drum, said casing forminga reservoir in which the drum may comsubmerged in pulp.

ing, in combination, a rotary filtering drum of polygonal cross section,a casingtherefor forming a reservoir for' unthickened pulp and having anopening at one 'sideof the drum for the discharge of thickened pulp,

said openingbeing below the normallevel of the pulp in said casing, saiddrum being separated from the parts of said casing at opposite sidesof-sald opening by a small 0 earance space normally sealed by a layer ofstock on the surface of the drum, and

means for drivin said drum,

6. A pulp thic ening apparatus corn" rising; in combination, a filteringrum mounted to rotate about a. substantially horizontal axis, means fordrivingsaid drum, a casing in which said drum is mounted,isaid casinforming a reservoir for pulp to be thickened and having a horizontalopening therem at one side of and drum for the discharge of thethickened pulp, said P ing eing below the normal level of the saidopening.

' the lower.

a filtering drum, ineans pulp thickening apparatus compr sunthickenedpulp in the casing, and means cooperating with said drum to prevent thedirect flow of unthickened pulp through Z. A pulp thickening apparatuscomprising, in combination, a filtering drum vnicninted to rotate abouta substantially horizontally axis, means for driving said drum, a casingin which said drum is mounted, said casing forming a reservoir for pulpto he thickened and having a horizontal opening thereinLat one side ofsaid drum for the discharge of the thickened pulp,said opening beingbelow the normal level of the Ila-- thickened pulp in the casing, and apart at side of said opening having an inner curved surface extend'infor a substantial distance circurn'ferentially of said drum andseparated from said drum by a narrow clearance space, whereby-said partcooperates with the drum to prevent the direct flow of unthickened pulpthrough said discharge opening. 8. A pulp thickening apparatuscomprising, in combination, aifilteringf drum mountv ed to rotateabout-a substantially horizontal axis, means for dri ing said drum, acasing in which said drum is mounted, said casing forming a reservoirfor pulp to be thickened and having a horizontal opening therein at oneside of said drum for the discharge of the thickened pulp, the normallevel of said opening being below thev nnthickened :pulp' in the casing,a part at the lower side of said opening having an inner curved surfaceextending for a substantial distance oil-1minferentially of said drumand separatedfi om said drum .fby anarrow clearance space,-

whereby said part cooperates withithe to prevent the" direct how ofunthickened pulp through said discharge opening, and means wherebysaidpart may he'adju'sted-to vary the width of said clearance space. 9A-pul thickening apparatus compris ing, in com ination, a filtering:drum mount-v ed to rotate about a substantially horizontal axis,me'ansfor' driving said drum, a casing in which said drum is mounted,said casing forming a reservoir forpulpto be thickened and having ahorizontal opening therein at one sideof said drum for the discharge ofthe thickened pulp, the normal level of the unthickenedpulp inthe-casing, and parts at the upper and lower sides of said openinghaving innervcurved surfaces extending for a substantial distance alongthe circumference of said drum and separated from the peripheral surfaceof said drum' 'by a. narrow clearance space, whereby said partscooperatewiththe rumed to rotate about a substantially horizontal saidopening being below axis, said drum being of polygonal cross section, acasing in which said drum is mounted, said casing being rovided with adischarge opening at one si e of the drum and having surfaces at theupper and lower sides of said opening lying closely adjacent to theperipheral surface of the drum, the space between said drum and saidsurfaces being normally sealed by a layer of stock on the surface of thedrum, and means for driving said drum.

11. A pulp thickening apparatus compris ing, in combination, a rotaryfiltering drum of polygonal cross section, a casing in which said drumis mounted, said casing being pro vided with a dischar e opening at oneside of the drum, and a p ate at one side of said discharge openinghaving a surface substantially concentric with the axis of the drum andpositioned close to the edges separating adjacent faces of the drum andof sufiicient dimension circumferentially of the drum to overlie atleast two of said edges simultaneously.

12. A pulp thickening apparatus comprising, in combination, a rotaryfiltering drum, a casing in which said drum is mounted, said casingcomprising upper and lower portions hinged together, a shaft mounted onsaid upper portion, and driving connections between said shaft and saiddrum.

13. A pulp thickening apparatus comprising, in combination, a filteringdrum mounted to rotate about a substantially horizontal axis, a casingin which said drum is mounted, said casing forming a reservoir in whichsaid drum may be submerged in unthickened pulp, means for rotating saiddrum,

vent the direct flow of unthickened pulp through said opening.

14:. A pulp thickenlng apparatus comprising, in combination, a filteringdrum of polygonal cross section, means supporting said drum for rotationabout a horizontal axis, a casing in which said drum is mounted, saidcasing forming a reservoir in which said drum may be submerged inunthickened pulp, means for rotating said drum, said casing having ahorizontal opening therein at one side of said drum for the discharge ofthe thickened pulp, and parts at the upper and lower edges of saidopening cooperating with said drum to prevent the direct flow ofunthickened pulp through said opening.

15. A pulp thickening apparatus compris-.

ing, in combination, an open ended filtering drum, a gear at each end ofsaid drum and secured thereto substantially at the periphcry of thedrum, a shaft for each of said gears, bearings supporting said shafts atopposite ends of the drum for rotation about a substantially horizontalaxis, a driving shaft, and inions carried by said driving shaft fordriving said gears.

In testimony whereof I name to this specification.

' CARLTON H. ALLEN.

have signed my

